1. Field of the Invention
The present invention relates to plain paper facsimile transceivers, namely to the method and apparatus for modifying, or retro-fitting, an existing low cost plain paper electrostatic copy machine to operate as a facsimile transceiver, as well as copier with the addition of a removable applique.
2. Description of the Prior Art
The majority of facsimile transceivers sold today incorporate a thermal printer for the received document despite the customer's clear preference for documents on plain paper. While there are plain paper facsimile machines in the marketplace, they carry a price tag that is at least four times the price of a thermal printer facsimile machine with the same features. The lowest cost plain paper facsimile technology available today uses a thermal print head for heating and transferring the received image from a mylar ink ribbon to a plain paper sheet. With these units the cost of the consumable ribbon becomes a major cost factor with significant usage of such a machine.
Given the high cost of an electrostatic printing facsimile machine, many organizations have their thermal printer facsimile machines located in close proximity to an electrostatic copier machine. This allows the receiver of the facsimile transmission to immediately copy the thermal printout from the facsimile machine and make a plain paper copy of it. This also results in a high consumables cost where the facsimile machine is heavily used.
Another option is the use of a computer with a facsimile modem card together with computer laser printer to provide plain paper receiving capability. A limitation of this approach is the lack of a scanner capability for transmitting documents already printed. To complete this system to make it totally useful requires a stand-alone full page scanner. Both the laser printer and the scanner are high cost items which makes this approach less attractive.
The demand for a fully integrated plain paper facsimile machine has been documented in several publications, for example an article that appeared in Network World on June 12, 1989, by Bruce Guptill entitled "Gee Whiz! why not a fax/scanner/printer/copier/phone/PC?". The present invention presents such a system.
Since the same unit can also serve as a printer, the closest art known to the applicant are combined copier/printers. The closest copier/printers are disclosed by Starkweather (U.S. Pat. No. 4,027,961) and Carley (U.S. Pat. No. 4,575,214). Starkweather describes a printer attachment for a high speed flash type copier which uses a moving photoreceptor belt. Starkweather's copier attachment contains a moving laser scanner. This scanner projects a raster image, a scan line at a time, onto the copying area. The scanner head in the attachment is physically moved from scan line to scan line positions to paint an entire image to be printed onto an implied temporarily fixed position photoreceptor. Upon the completion of reception of the image, the photoreceptor belt is advanced to accept the next image to be printed.
Carley also describes a printer attachment for a copier of the same type as does Starkweather, and specifically distinguishes his invention from that of Starkweather. Carley rotates the axis of the scanning head 90 degrees to permit simultaneous movement of either the photoreceptor or of the laser writing head to accomplish the scanning function. His approach assumes a fixed platen copier attachment wherein scanning occurs by movement of the copier's optical system with a moving laser beam directed into the field lens of the copier to allow the copier's moving optics to do the scanning.
Carley's approach is directed towards flash type copiers as noted in his patent at Col. 4, lines 3-22:
"For strobe-illumination copiers, such as the Xerox 8200, no further copier modification is required. However many copiers, such as this using drums, mechanically scan the original, rather than strobing it by moving the document glass, the lens 7, and/or internal mirrors such as 6. Copiers with such scanning mechanisms must be examined or a case-by-case basis and certain copiers will prove difficult to convert with my apparatus. However, most such mechanisms can be disabled easily by removing a part from the drive mechanism such as a pin or set-screw, or similar action, and a tool to perform this disablement would be part of the installation kit for a given copier. Once these reciprocating parts are disabled (frozen) these copiers will take my apparatus just like a strobe-type copier. For example, the curved-glass Xerox 3600 series copiers use a reciprocating mirror 6 which can be harmlessly jammed into the extreme retrace position to disable the scan. This procedure takes just seconds to do, or undo, with the proper tool." PA1 ". . . a further object that the apparatus be easily and quickly removed and the copier restored to an unaltered state . . . no significant alteration to the copiers and so will not invalidate copier service contracts . . . "
Carley's embodiment does not appear to meet his stated objectives of a truly removable applique that is used in conjunction with a copier that remains useful. For example, while Carley seeks (Col. 1, lines 41-46):
It is believed that his disclosed embodiments do not teach how this is to be accomplished.
It is also noted that Starkweather and Carley both consider only of fixed glass platen copiers with the device used with them requiring that they electrically interconnect to the internal circuitry of the copier.
It is advantageous to have a facsimile applique that does not need to be interconnected with the internal wiring of the copier with which it is used, that no internal mechanical changes be required even on a temporary basis, that can be easily and quickly attached and removed to and from the copier that it is to be used with the necessary alignment procedure being a relatively easy one, and that can be used with the least expensive plain paper electrostatic copiers having moving platens.